Burner holding device comprising a cooling system for a burner arrangement in an entrained flow gasifier

ABSTRACT

The instant invention relates to a burner holding device for burners, which is arranged on an entrained flow gasification reactor, wherein the burners ( 4, 5 ) are held in the burner holding device ( 7 ) and extend through a flange ( 11 ), which fixes the burner holding device ( 7 ) to the entrained flow gasification reactor ( 8 ) and extend through the burner holding device ( 7 ) into the entrained flow gasification reactor ( 8 ). The cooling device encompasses at least two cooling circuits ( 1, 2 ), which are independent from one another, wherein exactly one cooling circuit ( 1, 2 ) is at least partially assigned to each burner ( 4, 5 ), so that each burner ( 4, 5 ) is surrounded by a section of the cooling device on an-end facing the front surface and wherein at least one cooling circuit ( 1, 2 ) is at least partially assigned to the front surface for cooling. Below the flange ( 11 ) within the burner holding device ( 7 ) from top to bottom, 
     a layer ( 19 ) consisting of insulating casting compound, which is fire resistant up to at least 800° C. and comprises a heat conductivity in the range of from 0.02-0.8 W/m K, 
     a layer consisting of loose material ( 17 ), which is fire resistant up to at least 800° C., 
     a layer ( 18 ) consisting of heat-conducting casting compound, which is fire resistant up to at least 1800° C. and comprises a heat conductivity of 3-15 W/m K furthermore surrounds the burners ( 4, 5 ).

The invention relates to a burner holding device comprising a cooling system for burners, in particular for burners, which are arranged in operative connection with an entrained flow gasification reactor.

STATE OF THE ART

Different devices for cooling reactor burners are known from the state of the art.

In the case of the currently known constructions in the field of the burner holding devices of burner systems comprising pilot, main and ignition burners, which are in operative connection with reactors for entrained flow gasification, the designs for the cooling system of the burners are for the most part embodied as pipe coil system and comprise water supplies and discharges. The designs of the cooling device still raise constructional questions, so that such a cooling at the interface burner-reactor is ensured in response to an optimal system design and clever arrangement of the burners above the actual reactor, thus avoiding the overheating of components, which endangers the safety of the system. A safety risk because of a lack of cooling is created when an overheating leads to leakiness of parts of the arrangement and gases can thus escape from the system. Known systems thus raise questions relating to the safety and the maintenance; in most cases, an improved safety requires a high capital expenditure.

A device for burner fastening comprising an integrated cooling system is described in DE 269 065, for example. The chosen spring elements for the cooling pipe fastening, the arrangement of cooling pipes and the possibility of only integrating one burner leads to a danger of slagging in a disadvantageous manner at the outer edge of the reactor and to an output potential, which is too low for large reactors.

DE 44 16 037 C1 describes a device for closing an inspection opening and for fastening the burner for pressurized gasification reactors, which is characterized by a cooling disk for a specific cooling water supply and discharge as well as a special pipe suspension for the pipe system for the heat discharge. This solution also does not fulfill the demands on safety, ease of maintenance and cost expenditure, which are to be made on a system comprising a plurality of burners and large output for such reactors.

There is thus the demand for improving the system safety with reference to uncontrolled overheating of the reactor closure.

DISCLOSURE

Based on this state of the art, the present invention is based on the object of creating an improved burner holding device comprising a cooling system for a burner arrangement in an entrained flow gasifier. This object is solved by means of a device comprising the features of claim 1. Preferred embodiments are described in the dependent claims.

An embodiment of the invention relates to a burner holding device, which is arranged on an entrained flow gasification reactor. The burner holding device includes at least two burners, which are guided into the entrained flow gasification reactor. The burner holding device is closed towards the top by means of a flange, through which the burners and required supply and discharge lines extend. A cooling device is arranged in the burner holding device. Advantageously, it comprises at least two cooling circuits, which are independent from one another. The failure of the one cooling circuit can thus be compensated by the other cooling circuit. Each cooling circuit is furthermore assigned to only one burner, which, however, can advantageously be divided into sections, so that a further section is available for cooling the surface, which is located at the front side of the entrained flow gasification reactor. An even cooling can thus be ensured on the entire interface between reactor and burner. The cooling pipe coils, which form the cooling circuits, are arranged in a stable manner without further mounting by means of this construction in an advantageous manner. The layer design of the interior of the burner holding device, which initially consists from bottom to top of heat conducting and then of insulating material, is furthermore advantageous, so that the desired heat discharge takes place only at the desired areas, while overhead an unnecessary temperature loss of the system cannot take place.

Advantageously, the cooling device can be provided from cooling coils, which can be wound cleverly and without cooling gaps.

A further exemplary embodiment relates to the fact that at least 20% of the overall height of a burner are surrounded by a corresponding section of the cooling coil without cooling gaps, so that at least the hot zone of the burner, which encompasses temperatures from 1600° C. to 1800° C., is cooled reliably.

Even further embodiments disclose the advantageously independent charging of the independent cooling circuits, with coolant simultaneously.

Embodiments finally refer to the fact that said layer of insulating material is a sealing compound, which is fire resistant up to at least 800° C., comprising a thickness in the range of 2.0 kg/l, preferably below 1.5 kg/l. This can be lightweight refractory concrete.

Even further embodiments specify that the layer consisting of up to at least 800° C. fire resistant loose material is a fire clay granulate material or another lightweight refractory brick granulate material.

The heat conducting layer can furthermore be a refractory concrete, in particular a dense heavyweight refractory concrete, while the insulating layer advantageously is a non-dense refractory concrete.

These and further advantages become obvious from the following description.

BRIEF DESCRIPTION OF THE FIGURES

The reference to the figures in the description serves to support the description. Objects or parts of objects, which are substantially identical or similar, can be provided with the same reference numerals. The figures are only schematic illustrations of embodiments of the invention.

FIG. 1: shows a longitudinal section through the burner holding device according to the invention comprising the arrangement of the cooling system comprising burner fastening, main burners, start burner, individual cooling coils and cooling coil arrangement as well as layer materials.

FIG. 2: shows a top view of the reactor comprising a partial section.

DESCRIPTION

The device of the present invention serves for the improved cooling and thus for the improved system safety of a device, which is suitable to generate synthesis gas and which comprises one burner or a plurality of burners, which are arranged in operative connection with an entrained flow gasifier. Principally, the burner holding device according to the invention comprising a cooling system for burners serves to cool the space located around the burner or the burners and which extends from a side of the burner holding device facing the reactor, identified hereinbelow as “front surface of the reactor”, to a device for holding the burner or the burners, which will advantageously be a flange. A thermal overheating of the claimed components can be avoided by means of the provided cooling. In particular, seals, such as the flange seal, and individual flanges, which are arranged on the pipes holding the burners, are protected against overheating by reducing the temperature and it is avoided that the flanges, seals and other components are damaged by such an overheating, which could lead to the escape of gases, which contribute to the reaction, which is carried out. As is known to the person skilled in the art, such a gas escape holds an enormous potential of danger. The reduction of the temperature further serves to protect the material of involved components, thus reducing maintenance costs.

To provide an improved cooling system for such burners, which are coupled to an entrained flow gasifier and which are thus arranged at the front sides thereof and which are held there accordingly by a holding device, provision is thus made according to the invention for a plurality of cooling devices, which are independent from one another, which cool this front side as well as the hottest sections of the burners. The holding device for the burners, within which the cooling device is arranged, is identified herein as “burner holding device”. A plurality of pipe coil cooling systems operating independent from one another is provided as cooling devices. Systems for the production of synthesis gas, which encompass a burner as start burner, which is arranged in the center of the holding device and which encompass a plurality of burners as so-called main burners, so that they are arranged equally spaced apart from the central burner, if applicable, can thus be equipped with a so-called “inner cooling circuit” for cooling the central burner and with an outer cooling circuit for cooling the burners located outside of the center. Part of the burner holding device can be provided therewith by means of pipe coils for cooling outer and inner cooling circuits, which are independent from one another and which are identified hereinbelow as “bottom part”.

It is important thereby that different burners, such as start and main burners, which render different functions, such as different output, for instance, are cooled by means of cooling circuits, which are independent from one another, so as not to cause an overheating of the entire burner holding device in the event of a cooling circuit breakdown, if applicable. However, a cooling circuit can simultaneously be assigned to a burner and to a part of the front surface for cooling; however, it then encompasses virtually different sections, one horizontal section and one vertical section, which forms a collar around the burner in a manner of speaking.

On the one hand, a cooling is thus provided in the plane, which provides the interface between reactor and burner holding device (the front surface). On the other hand, the burners, such as start burner and main burner, for example, are additionally cooled in their lower area. Conventional burners are substantially embodied as pipes. They can already be cooled sufficiently by means of an at least partial cooling, which takes place around its hottest area, thus around the pipe end (referred to hereinbelow as lower end) of the burner facing the reactor by means of cooling pipe coils. It can thereby be sufficient to cool only the lower third of the burner. Advantageously, at least the lower fifth of the burner is cooled, thus approximately 20% of the burner height, based on its overall height within the burner holding device.

In the case of a different burner geometry, it makes sense for the burner to be wrapped with cooling coils to the extent that the zone in which temperatures of up to 1800° C. prevail, are cooled indirectly. The winding of the cooling coils of the cooling circuits of the different burners operating separately from one another is thereby guided such that no cooling gaps are created. Such a winding is known to the person skilled in the art.

The pipe coil length for the burner cooling of the individual burners, thus of the section of the pipe coil located as winding around the lower burner part, can be more than 20% of the overall length of the entire individual cooling system. The pipe coil cooling system, which is arranged around a main burner, can be sectioned into two or more individual systems. The wound pipe coil sections, which quasi form a “collar” on the lower part of the burner around the guide pipes thereof, are thus cooled in the same way as the collars, which are located around the guide pipes of the start burner, thus simultaneously to the pipe coil sections, which are located on the front side of the reactor. Thus, advantageously a closed cooling surface is provided on the front surface of the reactor and along the lower section of all of the burners, wherein the height of the collars can be chosen independent from one another. It is further advantageous that the cooling of the lower areas of the burners takes place simultaneously through the cooling circuits arranged independent from one another, so that the breakdown of a cooling circuit does not lead to an overheating of the entire burner holding device, because the further provided cooling circuits can compensate for the error.

To protect the side of the overall system facing the interior of the reactor and the bottom parts of the individual burners from thermal overheating, the cooling coil system of the individual cooling systems is designed such that the outer cooling system takes over the cooling of the upper side of the reactor as well as the cooling of the lower areas of the main burners. Advantageously, the cooling device according to the invention comprising the burner holding device thus presents a cooling, which goes beyond the cooling described in the state of the art, which furthermore provides for an improved safety by means of separate cooling circuits.

In the exemplary embodiments of the invention, the individual pipe coil cooling systems cool the surface of the burner holding device facing the reactor, thus also the lower areas of the main burners and of the start burner. The simultaneous cooling of individual burners and of said surface leads to particular advantages relating to construction of the type that a special mounting of the pipe coils is superfluous or not necessary. In response to the use of two cooling circuits, the pipe lengths for the respective section abutting on the plane and for the section forming the collar can be the same, so that 50% of the overall cooling is still provided in response to the breakdown of a cooling system.

In the case of a centrally arranged start burner, the cooling can take place such, that for instance the start burner comprising the inner cooling circuit, including the supply and discharge pipes for the cooling water, forms a constructive unit.

In the case of the burner holding device according to the invention, the outer cooling system for the main burner or the main burners can be fastened to a casing, which is fastened to a flange, the so-called main flange, which is located at the upper ends of the burners. The fastening can take place on a collar or projection. This casing also serves to accommodate further components, which hold the burners, which also take over protective functions with reference to the temperature control.

According to the invention, the main flange of the burner holding device, which will carry the essential portion of the pressure created in the system, and the further components are protected against overheating by means of the following arrangement.

Layers of heat-conducting and heat-insulating materials are provided within said casing below the flange, which form protection in many ways. The lower area of the burners, which are wrapped with the cooling coils such that so-called collars are formed, are cast with a mass, which has an application temperature of at least 1500° C., which is thus fire resistant up to this temperature and which shows a very good to good heat conductivity. The dense casting compounds comprising the main component silicon carbide having heat conductivities of from 5 to 15 W/m K at temperatures of 1000° C. as well as dense fire resistant concrete comprising the main components aluminum oxide and/or chromium oxide and/or silicon dioxide having heat conductivities of from 3.0 to 4.0 W/m K at temperature of 1000° C. are considered to be suitable masses for this lowermost layer. These fire resistant casting compounds can exhibit densities of from 2.4 to 3.6 kg/l. Preferred casting compounds can exhibit densities in the range of from 2.5 to 2.7 kg/l; on principle, however, such a suitable fire resistant mass or the refractory concrete can have a density of from 2.0 to 4.0 kg/l.

To protect the cooling coils of the burner holding device on the burner chamber side against the corrosive and chemical attack of the gas atmosphere and the slag, they can furthermore be provided with the studding and coating, which is common from the state of the art of power plant and gasification technology, comprising suitable SiC-containing ramming masses of high heat conductivity.

Underneath the main flange, the space between the burners is filled with an insulating, less dense casting compound, which exhibits a density in the range of from 1.0 to 2.0 kg/l. This includes the heat insulation and lightweight refractory concrete, which holds a high heat insulation comprising a heat conductivity of approximately 0.1 to 0.8 W/m K.

Between the layer consisting of highly insulating casting material at the main flange and highly heat-conducting material on the lower end of the burners, the space is filled with a loose, heat-insulating loose material, which can be a fire resistant insulation granulate material, for instance of fire clay or another lightweight refractory brick. The preferred density lies in the range of around 1 kg/l, the fire resistance is to lie at at least 800° C. A suitable grain size lies at 8 to 12 mm, a grain size of a diameter of approximately 10 mm is preferred.

The entrained flow gasification reactor itself also encompasses a cooling jacket, which extends upwards to the burner holding device such that it surrounds the front surfaces like a collar. This collar virtually surrounds the cooling system provided by the burner holding device. In the device according to the invention, the height of the outer ring of the burner holding device wound by the cooling pipes corresponds to the height of the wound collar of the cooling jacket of the reactor located opposite thereto, so that an annular gap is created between the two cooling systems. This gap can be adjusted with a gap width of 5 to 50 mm between the cooling elements, the cooling collar of the reactor and the wound outer ring of the burner holding device.

Advantageously, the adjusted annular gap is continuously flushed with inert gas, so that none or only negligible amounts of reaction gases, which eventually permeate into the annular gap, collect and corrosive forces can develop. The inert gas flushing of the annular gap thus also serves to protect the burner holding device. Towards the outside, the annular gap is filled with packages consisting of fire resistant flexible sealing cord, which consist of suitable ceramic fibers from the main component aluminum oxide and silicon dioxide, which ensure a sufficient permeability for the dispersion of the inert flushing gas for flushing the annular space and for securing the thermally-related relative motions of the cooling jacket as well as of the burner holding device as a whole.

According to the invention, the burner holding device is filled with loose heat-insulating loose material, as explained, and is defined against the main flange with a rolled jacket, the described casing, wherein the rolled jacket is held on the collar of the main flange by means of groove pins or other fastening devices. In so doing, the jacket can be disassembled downwards after removal of the groove pins in case of repair. The heat-insulating loose material thus falls out of the burner holding device and a replacement of the cooling element is possible without any problems after separating the cooling water pipes.

In the case of a centrally arranged start burner 4 and a locally arranged main burner 5, FIG. 1 shows an outer cooling circuit 1 and an inner cooling circuit 2 comprising the pipe coil section, the start burner cooling section 3, arranged at the start burner 4. The pipe coil section 6 takes over the cooling of the lower area of the main burners 5. The entire burner holding device 7, the components of which are substantially replaceable and which is arranged above the reactor system 8, also serves for the supply and discharge of the required cooling water quantities via the pressure joints and pipes 9, 10. As shown in FIG. 1, the cooling water for the cooling of the individual systems is supplied via the pressure joints 9, 10 and via further non-illustrated joints, which are welded to the main flange 11.

The cooling for the centrally arranged start burner 4 takes place via the cooling coil system, which takes over the cooling of the inner area of the overall system of the burner holding device 7 as well as of the lower part of the start burner 4. The fastening of the pipe coil system, which provides the outer cooling circuit 1, takes place at a separate casing 12, which is fixedly connected to the main flange 11 of the overall system. The main flange 11 is protected against excessive thermal stress by means of a system assembled from a plurality of components consisting of different heat-conducting materials, which comprises a loose heat-insulating material 17 for filling the cavity, a heat-conducting refractory concrete layer 18 and an insulating lightweight refractory concrete layer 19.

A section of the cooling coils extends on an outer edge of the burner holding device, while forming an outer ring 13, from the front face of the entrained flow gasification reactor upwards and at least along a part of the casing 12, wherein a height of the cooling coil pipes extending upwards corresponds to a height of a collar 14 of a cooling jacket of the entrained flow gasification reactor 8, so that an annular gap 15, which encompasses a gap width of from 5 to 50 mm, is provided between the collar 14 and the cooling coil pipes extending upwardly.

At the lower end of the burner holding device 7, the annular gap 15 is provided with a sealing cord package 20, which prevents the permeation of slag into the annular gap 15.

FIG. 2 shows the burner holding device 7 in the top view; three main burners 5 are surrounded by an outer cooling circuit 1, which is fed via the cooling water supply joints 9 and 10. The start burner 4 is surrounded by an inner cooling circuit 2, also fed by cooling water supply joints 9 and 10. The section of the inner cooling circuit 2 is the start burner cooling part 3.

Altogether, a considerable improvement as compared to available systems is already attained by means of the proposed solution in that the safety against overheating is improved by means of the separate cooling circuitry. A smart constructive arrangement of the pipe coils required for the cooling, which does not require any separate holding devices, is additionally provided. It is furthermore advantageous that the components of the burner holding devices, such as cooling coils or insulating materials, can be replaced.

List of Reference Numerals

1 outer cooling circuit for the main burners

2 inner cooling circuit for the start burner

3 start burner cooling section

4 start burner

5 main burner

6 main burner cooling section.

7 overall system burner holding device

8 entrained flow reactor

9 joint cooling water supply

10 joint cooling water discharge

11 main flange

12 casing of the cooling device in the burner holding device

13 outer ring

14 wound collar of the cooling jacket

14′ cooling jacket of the reactor

15 annular gap

16 annular space

17 insulating loose material

18 refractory concrete layer heat conducting

19 lightweight refractory concrete layer insulating

20 sealing cord package 

1. A burner holding device (7), which is arranged on an entrained flow gasification reactor (8), wherein at least two burners (4, 5) are held in the burner holding device (7) and extend through a flange (11), which fixes the burner holding device (7) to the entrained flow gasification reactor (8) and extend through the burner holding device (7) on a front surface of the entrained flow gasification reactor (8) into said entrained flow gasification reactor (8) and wherein a cooling device is arranged in the burner holding device (7), wherein the cooling device comprises at least two cooling circuits (1, 2), which are independent from one another, wherein different cooling circuits (1, 2) are at least partially assigned to different burners (4, 5), so that each burner (4, 5) is surrounded by a section of the cooling device on an end facing the front surface and wherein at least one cooling circuit (1, 2) is at least partially assigned to the front surface for cooling, and wherein below the flange (11) within the burner holding device (7) from top to bottom a layer (19) consisting of insulating casting compound, which is fire resistant up to at least 800° C. and comprises a heat conductivity in the range of from 0.02-0.8 W/m K, a layer consisting of at least 800° C. fire resistant loose material (17), a layer (18) consisting of heat-conducting casting compound, which is fire resistant up to at least 1500° C. and comprises a heat conductivity of 3-15 W/m K, surrounds the burners (4, 5).
 2. The burner holding device (7) according to claim 1, characterized in that the cooling circuits (1, 2), which are independent from one another, comprise cooling pipe coils and in that at least 20% of the overall height of a burner are surrounded by a section (3, 6) of the cooling coil without cooling gaps.
 3. The burner holding device (7) according to claim 1 or 2, characterized in that the independent cooling circuits (1, 2) can simultaneously be charged with coolant.
 4. The burner holding device (7) according to any one of the preceding claims, characterized in that the layer (19) of insulating casting compound, which is fire resistant up to at least 800° C., has a density in the range of 1.0 to 2.0 kg/l, preferably in the range of 1.0 to 1.5 kg/l.
 5. The burner holding device (7) according to any one of the preceding claims, characterized in that the layer (19) consisting of insulating casting compound, which is fire resistant up to at least 800° C., is lightweight refractory concrete.
 6. The burner holding device (7) according to any one of the preceding claims, characterized in that the layer consisting of loose material (17), which is fire resistant up to at least 800° C., is a fire clay brick granulate material or another lightweight refractory brick granulate material.
 7. The burner holding device (7) according to claim 6, characterized in that the fire resistant loose granulate material (17) encompasses a grain size in the range of from 8.0 to 12.0 mm diameter, preferably of 10.0 mm diameter.
 8. The burner holding device (7) according to any one of the preceding claims, characterized in that the heat-insulating layer (18) is a refractory concrete comprising a high heat conductivity in the range of 3 to 15 W/m K, preferably of 5 to 15 W/m K, and comprising a density in the range of 2.0 to 4.0, preferably in the range of 2.4 kg/l to 3.6 kg/l, most preferably in the range of 2.5 to 2.7 kg/l.
 9. The burner holding device (7) according to any one of the preceding claims, characterized in that the burner holding device (7) has a circular cross section and that a first burner is a start burner (4), which is arranged in the burner holding device (7) in a longitudinal axial manner and which is surrounded by an inner cooling circuit (2).
 10. The burner holding device (7) according to claim 9, characterized in that a plurality of further burners is arranged as main burners (5) spaced apart from the start burner (4) and are assigned to at least one outer cooling circuit (1).
 11. The burner holding device (7) according to any one of the preceding claims, characterized in that a casing, in particular a rolled jacket (12), which is fastened to a collar formed on the bottom side of the main flange (11), forms an inner limitation for the layers.
 12. The burner holding device (7) according to claim 10, characterized in that the outer cooling system for the main burners is fastened to the casing (12).
 13. The burner holding device (7) according to any one of claims 2 to 12, characterized in that a section of the cooling coils extends on an outer edge of the burner holding device from the front side of the entrained flow gasification reactor upwards and at least along a part of the casing (12), wherein a height of the cooling coil pipes extending upwards corresponds to a height of a collar (14) of a cooling jacket (14′) of the entrained flow gasification reactor (8), so that an annular gap (15) between the collar (14) and the cooling coil pipes extending upwards is provided, in particular an annular gap (15), which shows a gap width of 5 to 50 mm.
 14. The burner holding device (7) according to claim 13, characterized in that the annular gap (15) is filled with a fire resistant, flexible sealing cord (12) so as to form a seal.
 15. The burner holding device (7) according to any one of claims 2 to 14, characterized in that the sections of the cooling pipe coils of the at least two cooling circuits (1, 2), which are independent from one another, have the same length.
 16. The burner holding device (7) according to any one of claims 2 to 15, characterized in that the cooling pipe coils on the side facing the combustion chamber, are provided with a coating of fire resistant material comprising a high heat conductivity.
 17. The burner holding device (7) according to claim 16, characterized in that the coating consists of a material comprising a high silicon carbide content, which is held permanently by means of metal pins welded onto the pipe surface.
 18. The burner holding device (7) according to any one of claims 1 to 17, characterized in that the loose material (17) can be used repeatedly. 